The Twitter CEO also opposes the idea of regulating Twitter and other internet companies like a public utility.
Senators are outraged over online censorship, privacy invasion, secret data mining, fake news, hate speech, and disinformation warfare campaigns by foreign nations.
Facebook remains a leader in the digital advertising market with an estimated 20 percent share this year (second only to Google, which incidentally did not send a C-level exec to Wednesday's hearing).
"As [Sen. Richard Burr (R-N.C.)] has noted, 'Nothing less than the integrity of our democratic institutions, processes and ideals is at stake.' We agree, and we are determined to meet this challenge".
Google said Walker would be in Washington on Wednesday and be available to meet with lawmakers.
He added, "I know our members have a series of hard questions about structural vulnerabilities on a number of Google's platforms we need answers for".
This morning, Twitter CEO Jack Dorsey and Facebook COO Sheryl Sandberg appeared before the U.S. Senate Intelligence Committee to discuss foreign interference, specifically from Russian Federation, in U.S. elections via social media.
Sandberg said that Facebook was "too slow to spot" Russia's purported influence operation and "too slow to act".
"The actions we've taken in response. show our determination to do everything we can to stop this kind of interference from happening", Sandberg said. Earlier this year Facebook founder and CEO Mark Zuckerberg testified before lawmakers in part to explain how the personal information of tens of millions of Facebook users ended up in the hands of the United Kingdom -based data firm Cambridge Analytica.
Facebook and Twitter are using increasingly sophisticated technology and artificial intelligence to combat the misuse.
Dorsey argues the law allows the internet economy to flourish: "If we didn't have that protection, we would not be able to do anything around harassment or to improve the safety or health of the conversation around the platform".
Both said they're now working closely with the FBI's new election interference task force.
Conservative Republicans in Congress have, however, criticized social media companies for what they say are politically motivated practices in removing some content, a charge the companies have repeatedly rejected.
While Twitter has denied those claims, Dorsey had to admit mistakes while explaining the algorithms Twitter uses for its content.
He added: "And we're thwarting over a half million accounts from logging in to Twitter every day".